CSAT3B 3-D Sonic Anemometer with Integrated Electronics

Campbell Scientific’s CSAT3B 3-D Sonic Anemometer is an update and replacement to the original CSAT3, and remains the 3-D sonic anemometer of choice for eddy-covariance measurements. It has an aerodynamic design, a 10 cm vertical measurement path, operates in a pulsed acoustic mode, and withstands exposure to harsh weather conditions. Three orthogonal wind components (ux, uy, uz) and the sonic temperature (Ts) are measured and output at a maximum rate of 100 Hz.

The most conspicuous innovation of the new design is the elimination of the electronics box. Instead, the electronics are packaged inside the mounting block of the CSAT3B head. This design feature makes installation easier and offers greater flexibility in instrument placement.

Measurements can be triggered from three sources:

• Data logger SDM command

• Data logger CPI command

• CSAT3B internal clock

The SDM and CPI protocols both support mechanisms for synchronizing multiple CSAT3Bs.

Benefits and Features

• New conformal coating helps protect sonic transducers in corrosive environments

• Integrated electronics that provide easy mounting of a single piece of hardware

• Integrated inclinometer

• High-precision measurements ideal for turbulence and eddy-covariance studies

• An improved design with a thin, aerodynamic support strut close to the ends of the sensor arms, creating greater rigidity and improved accuracy of sonic temperature

• Data logger sampling supported for any frequency between 1 and 100 Hz

• New CPI communications for more robust, higher bandwidth measurements

• Multiple communication options including SDM, CPI, USB, and RS-485

• Internal temperature and humidity measurements with easily replaced desiccant

• Version 5 algorithm for calculating data outputs; combines the signal sensitivity of version 3 with the rain performance of version 4

• Includes options to filter high frequencies for applications requiring analysis of non-aliased spectra